Various apparatus have been used for removing earth in a tunneling operation including the use of remotely controlled boring apparatus which are basically augers, to the use of digging machines such as back hoe type equipment. While such tunneling machines provide for flexibility and production in the digging of tunnels, they do suffer drawbacks especially in certain soil conditions. In unstable soil conditions or where the soil is saturated with moisture, there can be soil creep, which can reduce the efficiency of the digging operation. The situation especially arises if for example, the machine has been left at the tunnel face overnight. In some circumstances, it may be necessary to remove the soil creep before the tunneling operation can continue. Alternatively in such situations it may be necessary to provide for continuous operation of the machine.
In addition, should it be necessary to work on the machine for maintenance this may require that the machine be either backed away from the face or removed entirely from the tunnel. Otherwise the presence of the potential for the soil creep at the face of the tunnel may interfere with the maintenance operations of the machine.
There thus remains a need for a apparatus for a tunneling machine to overcome the above disadvantages of the prior art.